Derivatives of 2-formyl-3-carbonamidoqui noxaline-di-n-oxides

ABSTRACT

2-Formyloximido-3-aminocarbonylquinoxaline-1,4-di-N-oxides are antimicrobial agents. The compounds, of which 2formylcarbomethoxyhydrazine-3-dimethylaminocarbonylquinoxaline1,4-di-N -oxide is a typical embodiment, are prepared from the reaction of the corresponding 2-bis(halogeno) methyl-quinoxaline derivative and hydroxylamine or an appropriate hydrazinocarbonic acid ester in the presence of a primary or secondary amine and water.

United States Patent 1 1 Seng et a1.

1111 3,839,326 14 1 Oct. 1,1974

7 [22] Filed:

1 DERIVATIVES OF 2-FORMYL-3-CARBONAMIDOQUI NOXALINE-DI-N-OXIDES [75] Inventors: Florin Seng, Cologne; Kurt Ley,

Odenthal-Globusch; Karl Georg Metzger, Wuppertal-Elberfeld, all of Germany [73] Assignee: Farbenfabriken Bayer Aktiengesellschaft, Leverkusen,

Germany May 1, 1972 21 Appl. No.: 249,121

[30] Foreign Application Priority Data May 7, 1971 Germany 2122572 ['52] US. Cl. 260/240 G, 99/2 AB, 99/4, 424/251, 260/243 B, 260/247. 1,

[51] Int. Cl..., C07d 51/78 [58] Field of Search..... 260/250 ON, 240 G, 243 B,

[56] References Cited UNITED STATES PATENTS 3,371,090 2/1968 .lohnston...'.., 260/240 G Ley et a1. 260 250 0N Berkelhammer et al..... 260/250 ON OTHER PUBLICATIONS McBee et al., J. Org. Chem, Vol. 30, pgs. 3,698 to Houben-Weyl, Methoden der Organischen Chemie, Band X/l, p. 1119, Georg Thieme Verlag, Stuttgart Germany (1971).

Primary Examiner-John D. Randolph 57 ABSTRACT 40 Claims, No Drawings formula:

i 1s l \N/ CH=Z l wherein each of R and R independent of the other, is hydrogen, lower alkyl, hydroxy(lower alkyl), (lower alkoxy) lower alkyl, cyclopentyl, cyclohexyl' or cycloheptyl, or R and R together with the nitrogen atom to which they are attached, are pyrrolidino, piperidino, hexam-ethyleneimino, morpholino or thiomorpholino; and a Z is Y vl #:sauwkas in which Y is an oxygen or sulfur atom and R" is lower alkyl, hydroxy(lower alkoxy), lower alkoxy, pyridyl, or -NR R* in which each of R and R, independent of the other, is hydrogen, lower alkyl, hydroxy (lower alkyl) or lower alkoxy(lower alkyl), or R and R together with the nitrogen atom to which they are attached, are pyrrolidino, piperidino, hexamethyleneimino, morpholino or thiomorpholino.

The term lower alkyl denotes a univalent saturated branched or straight hydrocarbon chain containing from one to six carbon atoms. Representative of such lower alkyl groups are thus methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec.butyl, tert.butyl, pentyl, isopentyl, neopentyl, tert.pentyl, hexyl, and the like.

The term lower alkoxy denotes a straight or branched hydrocarbon chain bound to the remainder of the molecule through an ethereal oxygen atom as, forexample, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy and hexoxy.

These compounds are obtained by allowing a 2-bis (halogeno)methyl-3-carbonamidoquinoxaline to react with hydroxylamine or hydrazine derivative in the presence of a primary or secondary amine. This'reaction may be represented as follows:

CON I 0 or o R2 H1Z I 'l' H amine \N CHX:

In the above, X is chloro or fluoro and R, R and Z are as defined above. r

The reaction is carried. out at temperatures from about 0 to about 50C. preferably between 10 and 30C, at normal or elevated pressure, generally normal pressure.

Preferably l to 2 mols of the hydrazine reactant or hydroxylamine, and preferably 2 mols of the primary or secondary amine are used per mol of the bishalogenomethyl compound. The amount of the amine employed can however be varied within wide limits. The nature of the primary or secondary amine used is relatively unimportant and it is possible to use alkyl, aralkyl, or aromatic amines such as methylamine, ethylamine, propylamine, dimethylamine, methylethylamine. ethylpropylamine. diethylamine and the like. The amines can be introduced into the reaction solution as gases or be in the form of their aqueous solutions. The reaction is preferably conducted in an inert organic solvent, particularly a polar organic solvent such as alkanol, as for example methanol or ethanol; alkanoic nitriles such as acetonitrile, dimethylformamide and the like. Mixtures of these and of water can also be employed. It is advantageous to carry out the reaction in the presence of water, preferably of 0.1 to 50. especially l to 20 percent by weight of water relative to the weight of the solvent. Even catalytic amounts of water can favor'ably influence the reaction. Thus the bis(- halogeno)methyl compound is suspended in one of the solvents, hydroxylamine or the hydrazine derivative and water are added, and approximately the calculated amount of a primary or secondary amine is added dropwise, with cooling if necessary. The compounds thus produced are isolated by convention methods.

The quinoxaline derivatives of this invention show strong antimicrobial effects. This activity can be ob served against Gram positive and Gram negative bacteria, such as: Enterobacteriaceae, for example Escherichiae, especially Escherichia coli: Proteae, for example Proteus vulgaris, Proteus mirabilis, Proteus morganii and Proteus rettgeri: Klebsielleae, for example Klebsiella pneumoniae; Salmonelleae; Pseudomonadaceae, for example Pseudomonas aeruginosa; Aeromonas, for example Aeromonas liquefaciens; Clostridia, for example Clostridium botulimmz and Clostridium tetani; Cocci, especially Staphylococci, for example Staphylococcus aureus; Streptococci, for example Streptococcus progenes; Enterococci, for example Streptococcus faecalis; Mycoplasmae, for example Mycoplasma pneumoniae and Mycoplasma hominis; Mycobacteria; Pasteurella, for example Pasteurella mulrocida; and Bordetella. for example Bordetella bronchisepticaAs a result of this activity and their low toxicity, the compounds are useful in human and veterinary medicine in the treatment of infections in animals caused by Gram positive and Gram negative bacteria and by mycoplasma. Infections of the respiratory tracts in poultry, especially in chicks, and mastitis of cows can be mentioned as particularly responsive to such treatment.

The method of treatment of microbial infections in animals according to this invention comprises the administration to the animal of an antimicrobially effective amount of a quinoxaline of Formula I. The amount administered will of course depend upon the nature and severity of the infection, whether the treatment is curative or prophylactic, the age and condition of the recipient of the treatment and the method of administration and dosage regimen. Generally, however, a suitable response is observed with daily doses of from 1 to The compoundsof the present invention are administered parenterally or orally in any of the usual pharmaceutical forms. These include solid and liquid oral unit dosage" forms such as tablets, capsules, powders, suspensions, solutions, syrups and the like, including sustained released preparations, and fluid injectable forms such as sterile solutions and suspensions. The term unit dosage form as used in this specification and the claims refer to physically discrete units to be administered in single or multiple dosage to animals, each unit containing a predetermined quantity of active material in association with the required diluent, carrier or vehicle.

The quantity of active materialjis that calculated to produce the desired therapeuticeffect upon administration of one or more of such units.

Powders are prepared by comminuting the compound to a suitable fine size and mixing with a similarly comminuted diluent pharmaceutical carrier such as an edible carbohydrate material as for example, starch. Sweetening, flavoring, preservative, dispersing and coloring agents can also be present.

Capsules are made by preparing a powder mixture as described above and filling formed gelatin sheaths. A lubricant such as talc, magnesium stearate and calcium stearate can be added to the powder mixture as an adjuvant before the filling operation; a glidant such as colloidal silica may be added to improve flow properties; a disintegrating or solubilizing agent may be added to improve the availability of the medicament when the capsule is ingested.

Tablets are made by preparing a powder mixture, granulating or slugging, adding a lubricant and disintegrant and pressing into tablets. A powder mixture is prepared by mixing the compound, suitablycomminuted, with a diluent or base such as starch, sucrose, kaolin, dicalcium phosphate and the like. The powder mixture can be granulated by wetting with a binder such as syrup, starch paste, acacia mucilage or solutions of cellulosic or polymeric materials and forcing through a screen. As an alternative to granulating, the powder mixture can be run through the tabletmachine and the resulting imperfectly formed slugs broken into granules. The granules can be lubricated to prevent sticking to the tablet forming dies by meansof the addition of stearic acid, a stearate salt, talc or mineral oil. The lubricated mixture is then compressed into tablets. The medicaments can also be combined with free flowing inert carriers and compressed into tablets directly without going through the granulating or slugging steps. A protective coating consisting of a sealing coat of shellac, a coating of sugaror polymeric material and a polish coating of wax can be provided. Dyestuffs can be added to these coatings to distinguish different unit dosages.

Oral fluids such as syrups and elixirs can be prepared in unit dosage form so that a given quantity, e.g-., a teaspoonful, contains a predetermined amount of the compound. Syrups can be prepared by dissolving the compound in a suitably flavored aqueous sucrose solution while elixirs are prepared through the use of a nontoxic alcoholic vehicle. Suspensions can be formulated by dispersing the compound in a non-toxic vehicle in which it is insoluble.

In addition to their therapeutic use, the new compounds can also be used to promote the growth and im-' prove feed utilization in animals, especially in raising young animals and fat-stock animals, as for example, calves, piglets and chicks.

The compounds can be administered in the feedstuff, in special feedstuff preparations, in preparations containing vitamins and/ormineral salts, or in the drinking water. Suchadministration of the compounds permits prevention or treatment of infections caused by Gram negative and by Gram positive bacteria and by mycoplasma, and additionally contributes to a more rapid growth of the animals and to better feed efficiency. In this embodiment, thecompounds are preferably mixed into the feedstuff or the drinking water in a concentration of l to 200 ppm.

The use of these compounds as feed additives can be seen from the following feeding experiments (Table D).

Chicks in groups of 12 were kept in cages and supplied with water ad libitum and a complete chick feed into which was intimately mixed the indicated amount of the test compound. The results are as follows:

Table D Average Weight Absolute Weight Relative Weight initial Weight of each animal lncrease (g) of lncreaseU/r (g) of each after each animal after after Concentration animal 14 days 28 days 14 days 28 days 14 days 28 days Test 1 Control 0 59.3 170.8 335.2 111.5 275.9 100.0 100.0

Compound 01' Example 20 59.3 179.2 346.6 119.9 287.3 107.4- 104.1

Test 2 Control 0 59.1 168.3 351.6 109.2 292.5 100.0 1000 Compound of 10 59.1 173.3 358.3 114.2 299.2 104.5 1022 Example 20 20 59.1 175.8 360.0 116.7 300.9 102.8

' methylar ninocarbonylquinoxalinel ,4-di-N-oxide The following examples will serve to further typify the nature of this invention without a limitation on the scope thereof:

EXAMPLE 1 2-formylcarbomethoxyhydrazone-3- methylaminocarbonylquinoxalinel ,4-di-N-oxide 0 r l0 jioormom CH N NH 00 H;

g (0.2 mol) of 45% strength aqueous dimethylamine solution are slowly added dropwise, with stirring, to a suspension of 30.2 g (0.1 mol) of 2-dichloromethyl-3- methylaminocarbonylquinoxaline-l ,4-di-N-oxide (Reactant A) and 10 g (0.1 1 mol) of hydrazinocarbonic acid monomethyl ester (Reactant B) in 120 ml of alcoliol and lil mlofwaterfAfter 5 hours the product is filtered off and g (78.5 percent of theory) of 2- formylcarbomethoxyhydrazine-3- 5 are obtained as yellow crystals which after recrystallization from acetic acid melt at 228C, with decomposition.

' Analysis: m ta s s Calculated: c Found: C

The 2-dichloromethyl-3-carboxylic acidmethylamidoquinoxaline di-N-QXide required as the starting compound, of the formula CONHCH:

CHCI:

Analysis: C,,H,,Cl N -;O;, (302) Calculated: C 43.7% H 2.98% Cl 23.6% Found: 'C 43.2% H 3.1% Cl 23.1%

The remaining dichloro compounds required as starting compounds are obtainable analogously.

EXAMPLES 2-37 the following reactants are allowed to react:

Example N0. Reactant A 2-9 Z-dichloromethyl-3-dimethylaminocarboxylquinoxaline-l.4-dioxide l0 2-dichloromethyl-3-piperidinocarboxylquinoxaline-l .4-dioxide ll 2-dichloromethyl-3-diethylaminocarboxylquinoxaline-l.4-di0xide l2 2-dich|oromethyl-3pyrro|idinocarboxylquinoxaline-l .4-dioxide l3 2-dichloromethyl-3-methylaminocarboxylquinoxaline-l .d-dioxide l4 2-dichloromethyl-3-B-hydroxyethylaminocarboxylquinoxaline-l,4-dioxide l5 2-dichloromethyl-3-n-propylaminocarboxylquinoxalinel l-dioxide l6 Z-dichloromethyl-3-cyclohexylaminocarboxylquinoxaline-l .4-dioxide I7 2-dichlor0methyl-3-isopropylaminocarboxylquinoxalinel ,4-dioxidel8 Z-dichloromethyl-B-ethylaminocarboxylquinoxaline-l .4-dioxide l9 Z-dichloromethyl-3-methylaminocarboxylquinoxaline-l ,4-dioxide -Continued Example Nov Renctant A 20 Zdichloromethyl-3-B-hydroxyethylaminocarboxylquinoxaline-l.4 dioxide 2l 2-dichloromethyl-3-morpholinocarboxylquinoxaline-l .4-dioxide 22 Z-dichloromcthyl-3-ethylaminocarboxylquinoxaline-l .4-dioxide 23 Z-dichloromethyl-3-n-propylaminocarboxylquinoxaline-l .4-dioxidc 24 2-dichloromethyl-3-i-propylaminocarboxylquinoxuline-l .4-dioxidc 25-26 2 dichloromethyl-3-methylaminocarboxylquinoxalineJ .4-dioxide 27-29 2-dichloromethyl-3-[3-hydroxyethylcarboxylquinuxaline-l .4-dioxide 30-33 2-dichloromethyl-lB-methoxyethylcarboxylquinoxalinel .4-dioxide 34 2-dichIoromethyl-3-diethyluminocarboxylquinoxaline-l .4 dioxide 35 Z-dichloromethyl-li morpholinocarboxylquinoxaline-l .4-dioxide 36 2-dichloromethyl-3-piperidinocarboxylquinoxnlined .4-dioxide 37 Z-dichloromethyl-Ii-pyrrolidinocarboxylquinoxaline-l .4 dioxide Example N0. Reactant B 2 hydrazinocarbonic acid methyl ester 3 hydrazinocarbonic acid fi-hydroxy ethyl ester 4 hydrazinocarbonic acid ethyl ester 5 hydrazinocarboxamide 6 N-morpholinocarbonylhydrazine 7 isonicotinoylhydrazine 8 hydroxylamine 9 hydrazinothiocarboxamide 10-18 hydrazinocarhonic acid methyl ester 19-20 hydroxylamine 2l hydrazinocarbonic acid methyl ester 22-24 hydroxylamine 25 hydrazinocarbonic acid B-hydroxyethyl ester 26-27 hydrazinocarbonic acid ethyl ester 28 hydrazinocarbonic acid B-hydroxyethyl ester 29 N-morpholinocarbonylhydrazine 30 hydrazinocarbonic acid methyl ester 3l hydrazinocarbonic acid ethyl ester 32 hydroxylaminc 33 hydrazinocarbonic acid B-hydroxyethyl ester 34-37 hydroxylamine R1 N/ Meltiiiglg Example D number R: Z

a1 NH-GHz-CHz-OCHL NNHfi-OC;H5 219 H :32 NH-OHzCHr-OCH:. NOH 21o v.33 NHCHzCH1OCHa NNH-(|J|-O-GHCHOH 21s a4 01H. NOH 200-202 35 NOH 212 36 NOH 200-201 NOH 210-211 What is claimed is: 1'. A compound of the formula:

wherein each of R and R independent of the other, is hydrogen, lower alkyl, hydroxy(lower alkyl), (lower alkoxy)lower alkyl, cyclopentyl, cyclohexyl or cycloheptyl, or

R and R together with the nitrogen atom to which they are attached, are pyrrolidino, piperidino, hexamethyleneimino, morpholino or thiomorpholino; and

Z is

2. A compound according to claim 1 wherein each of r R, R independent of the other, are hydrogen, methyl,

ethyl, propyl, 2-hydroxyethyl, Z-methoxyethyl, cyclohexyl or R and R together with the nitrogen atom to which they are attached, are pyrrolidino, piperidino or morpholino; and R is amino. morpholino, pyridino,

methoxy, ethoxy or 2-hydroxyethoxy.

3. The compound according to claim 1 which is formylcarbomethoxyhydrazine-3- dimethylaminocarbonylquinoxalinel ,4-di-N-oxide.

4. The compound according to claim 1 which is formylcarbomethoxyhydrazine-3- morpholinocarbonylquinoxalinel ,4-di-N-oxide.

5. The compound according to claim 1 which is formylcarbomethoxyhydrazine-3- diethylaminocarbonylquinoxalinel ,4-di-N-oxide.

6. The compound according to claim I which is formylcarbomethoxyhydrazine-3- pyrrolidinocarbonylquinoxaline-l ,4-di-N-oxide.

7. The compound according to claim 1 which is 2- formyloximido-3-(2- 1 v hydroxyethyl )aminocarbonylquinoxalinel ,4-di-N- oxide.

8. The compound according to claim 1 which is 2- formylcarbomethoxyhydrazine-3- piperidinocarbonylquinoxalinel ,4-di-N oxide.

9. The compound according to claim 1 which is 2- formyloximido-3-ethylaminocarbonylquinoxalinel ,4- di-N-oxide.

10. The compound according to claim 1 which is 2- formyloximid0-3-n.-propylaminocarbonylquinoxaline- 1,4-di-N-0xide.

11. The compound according to claim 1 which is 2- formyloximido-3-i.-propylaminocarbonylquinoxalinel ,4-di-N-oxide.

12. The compound according to claim 1 which is 2- f0rmylcarbo-(2-hydroxyethoxy)hydrazine-3- methylaminocarbonylquinoxaline-l ,4-di-N-oxide.

13. The compound according to claim 1 which is 2- formylcarbethoxyhydrazine-3-methylaminocarbonylquinoxaline-l ,4] -di-N-0xide.

14. The process for the preparation of a compound of the formula:

wherein each of R and R. independent of the other. is hydrogen. lower alkyl, hydroxy(lower alkyl), (lower alkoxy)lower alkyl. cyclopentyl. cyclohexyl or cycloheptyl, or R and R. together with the nitrogen atom to which they are attached, are pyrrolidino, piperidino, hexamethyleneimino. morpholino or thiomorpholino; and

Z is

in which Y is an oxygen or sulfur atom and R is lower alkoxy, hydroxy(lower alkoxy), lower alkoxy(- l t ltieyi ylt r -NR.K'.. n.1 hish.eah of Bi and R. ihdependent ot' the other, is hydrogen, lower alkyl. hydroxyflower alkyl) or lower alkoxy(lower alkyl), or R and RR together with the nitrogen atom to which they are attached. are pyrrolidino, piperidino. hexamethyleneimino, morpholino or thiomorpholino. which comprises treating a 2-dihalogenomethyl-3- carbonamidoquinoxaline-di-N-oxide of the formula:

i m g C-N/ I N/ OHXI wherein R and R are as herein defined and X is a halogen atom with hydroxylamine or a compound of the formula:

wherein Y and R are as herein defined. in the presence of a diluent and a primary or secondary amine and water at a temperature of 0 to 50 C.

15. The compound according to claim 1 which is 2- formylcarbomethoxyhydrazone-3- methylaminocarbonyl-quinoxazline-l.4-di-N-oxide.

16. The compound according to claim 1 wherein R and R are each methyl and Z is N-N- H-C00-CH,-CH,-OH.

21. The compound according to claim 1 wherein R t of R and R is hydrogen and the other is propyl and Z is N--NH-COOCH,. v

26. The compound according to claim 1 wherein one of R and R is hydrogen and the other is cyclohexyland Z is NNHCO-OCH 27. The compound according to claim I wherein one of R and R is hydrogen and the other is isopropyl and Z is N-NH-CO-OCH 28. The compound according to claim 1 wherein one of R and R is hydrogen and the other is ethyl and Z 29. The compound according to claim 1 wherein one of R and R is hydrogen and the other is methyl and Z is NOH.

30. The compound according to claim 1 wherein one 'of R and R is hydrogen and the other is hydroxyethyl :2n.Z.

31. Thefc'dhipe'irid accrciihitdliiifi niacin one of R and R is hydrogen and the other is hydroxyethyl .and Z is 32. The compound according i6 claim 1 wh erein one :of R and-R is hydrogen and the other is hydroxyethyl .and Z is N-NH-E- 17. The compound according to claim 1 wherein R and R are each methyl HCO0C,H,.

18. The compound according to claim 1 wherein R and R are each methyl and Z is NNHCONH,.

19. The compound according to claim I wherein R and R are each methyl and Z is 20. The compound according to claim I wherein R and R are each methyl and Z is and Z is N-N- 33. The compound according to claim 1 wherein one of R and R is hydrogen and the other is methoxyethyl and Z is N-NH-oo cm."

34. The compound according to claim 1 wherein one of R and R is hydrogen and the other is methoxyethyl and Z is 35. The compound according to claim 1 wherein one of R and R is hydrogen and the other is methoxyethyl and Z is NOH.

and R are each ethyl and Z is NOH.

are attached are H 15 v 16 36. The compound according to claim 1 wherein one 39. The compound according to claim 1 wherein R of R and R ishydrogen and the other'is methoxyethyl and R together with the nitrogen atom to which they and Z is are attached are N-NH--CCH:CH;0H.' N

m and R together with the nitrogen atom to which they are attached are 37; The compound according to claim 1 wherein R 38. The compound according to claim 1 wherein R and R together with the nitrogen atom to which they 

1. A COMPOUND OF THE FORMULA:
 2. A compound according to claim 1 wherein each of R1, R2, independent of the other, are hydrogen, methyl, ethyl, propyl, 2-hydroxyethyl, 2-methoxyethyl, cyclohexyl or R1 and R2, together with the nitrogen atom to which they are attached, are pyrrolidino, piperidino or morpholino; and R3 is amino, morpholino, pyridino, methoxy, ethoxy or 2-hydroxyethoxy.
 3. The compound according to claim 1 which is 2-formylcarbomethoxyhydrazine-3-dimethylaminocarbonylquinoxaline-1, 4-di-N-oxide.
 4. The compound according to claim 1 which is 2-formylcarbomethoxyhydrazine-3-morpholinocarbonylquinoxaline-1,4-di-N -oxide.
 5. The compound according to claim 1 which is 2-formylcarbomethoxyhydrazine-3-diethylaminocarbonylquinoxaline-1, 4-di-N-oxide.
 6. The compound according to claim 1 which is 2-formylcarbomethoxyhydrazine-3-pyrrolidinocarbonylquinoxaline-1,4-di-N -oxide.
 7. The compound according to claim 1 which is 2-formyloximido-3-(2-hydroxyethyl)aminocarbonylquinoxaline-1,4-di-N-oxide.
 8. The compound according to claim 1 which is 2-formylcarbomethoxyhydrazine-3-piperidinocarbonylquinoxaline-1,4-di-N -oxide.
 9. The compound according to claim 1 which is 2-formyloximido-3-ethylaminocarbonylquinoxaline-1,4-di-N-oxide.
 10. The compound according to claim 1 which is 2-formyloximido-3-n.-propylaminocarbonylquinoxaline-1,4-di-N-oxide.
 11. The compound according to claim 1 which is 2-formyloximido-3-i.-propylaminocarbonylquinoxaline-1,4-di-N-oxide.
 12. The compound according to claim 1 which is 2-formylcarbo-(2-hydroxyethoxy)hydrazine-3-methylaminocarbonylquinoxaline -1,4-di-N-oxide.
 13. The compound according to claim 1 which is 2-formylcarbethoxyhydrazine-3-methylaminocarbonylquinoxaline-1,4l -di-N-oxide.
 14. The process for the preparation of a compound of the formula:
 15. The compound according to claim 1 which is 2-formylcarbomethoxyhydrazone-3-methylaminocarbonyl-quinoxazline-1,4-di-N -oxide.
 16. The compound according to claim 1 wherein R1 and R2 are each methyl and Z is N-NH-CO-O-CH2-CH2-OH.
 17. The compound according to claim 1 wherein R1 and R2 are each methyl and Z is N-NH-CO-O-C2H5.
 18. The compound according to claim 1 wherein R1 and R2 are each methyl and Z is N-NH-CO-NH2.
 19. The compound according to claim 1 wherein R1 and R2 are each methyl and Z is
 20. The compound according to claim 1 wherein R1 and R2 are each methyl and Z is
 21. The compound according to claim 1 wherein R1 and R2 are each methyl and Z is NOH.
 22. The compound according to claim 1 wherein R1 and R2 are each methyl and Z is N-NH-CS-NH2.
 23. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is methyl and Z is N-NH-CO-OCH3.
 24. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is hydroxyethyl and Z is N-NH-CO-OCH3.
 25. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is propyl and Z is N-NH-CO-OCH3.
 26. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is cyclohexyl and Z is N-NH-CO-OCH3.
 27. The compound according to claim 1 Wherein one of R1 and R2 is hydrogen and the other is isopropyl and Z is N-NH-CO-OCH3.
 28. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is ethyl and Z is N-NH-CO-OCH3.
 29. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is methyl and Z is NOH.
 30. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is hydroxyethyl and Z is
 31. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is hydroxyethyl and Z is
 32. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is hydroxyethyl and Z is
 33. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is methoxyethyl and Z is
 34. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is methoxyethyl and Z is
 35. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is methoxyethyl and Z is NOH.
 36. The compound according to claim 1 wherein one of R1 and R2 is hydrogen and the other is methoxyethyl and Z is
 37. The compound according to claim 1 wherein R1 and R2 are each ethyl and Z is NOH.
 38. The compound according to claim 1 wherein R1 and R2 together with the nitrogen atom to which they are attached are
 39. The compound according to claim 1 wherein R1 and R2 together with the nitrogen atom to which they are attached are
 40. The compound according to claim 1 wherein R1 and R2 together with the nitrogen atom to which they are attached are 